An iOS developer is responsible for:

Mainly developing and designing innovative applications supplied by the iOS operating system. Being proficient with at least one of the two programming languages used. Either Objective-C or Swift. Having a compelling understanding of diverse patterns and practices belonging to the iOS channel. Freely creating project solutions by using Object-Oriented-Design method. Collaborating with a team of iOS developers in redefining and implementing new features. Generating unit-test which would ensure the over-all reliability and usage of codes. Making use of improvement methods like bug fixing for the betterment of the application performance. Working jointly with product management and UX to implement a concept by making use of a remarkable software design, coding, and processes. Constantly evaluating, maintaining, improving, and adapting new technologies available to ensure maximum use of applications.